Radiator cap



Feb. 21, 1939. y l Av WHW'E ET AL 2,147,727

RADIATOR CAP Filed Sept. 3, 1956 Patented Feb. 21, 1939 UNITED USTATESPATENT OFFICE.

2447.727 RADIATOR cAP Application September s` claims.

This invention relates to fluid pressure responsive means to lock aclosure member against removal when a pressure differential existsbetween the interior and exterior of an engine cooling system or thelike.

There are certain well known advantages to be obtained if thecirculating liquid in an engine cooling system is maintained under a fewpounds pressure and a number of automobile manufacturers have adoptedthe closed system which includes a blow-off valve acting automaticallyto relieve excess pressure through the overflow vent pipe. In a systemof this kind it is here proposed to prevent removal of the ller cap attimes when internal pressures are present, in order to avoid thepossibility of injury by scalding, damage to the car nish, loss ofcooling liquid and other undesirable resultants of vomition of thesystem contents through the filler opening.

In a preferred embodiment of the invention as designed for convenience,compactness, econorny and simplicity, there is provided as a part ofthedetachable cap assembly a movable plunger fitting the ller opening foroutward projection under internal system pressure into position toengage a`flxed abutment which holds the cap assembly against removal.Also incorporated in the cap assembly is a spring seated valve which.opens a port in the plunger to communicate the system with the overiiowvent pipe leading from the filler spout for the relief of pressure inexcess of a predetermined value.

For a better understanding of the structure involved reference may bemade to the accompanying drawing wherein Figure 1 is a side elevation ofthe cooling radiator and 'its connections with the front of the engine;Figure 2 is a vertical sectional view of the filler assembly; Figure 3is a similar view with the parts in position to prevent removal of thefiller cap; Figures 4 and 5 are, respectively, sectional views i takenon line 4-4 of Figure 2 and line 5-5 of Figure -3, and Figure 6illustrates the application of the invention to an alternate type of capretainer. l

.In the drawing the radiator fan I and the pump assembly 2 aremounted ona common shaft driven by a belt 3 from the engine crankshaft, 'fordrawing air through the radiator core 4 and circulating water or othercooling medium through the system. The system includes the radiator core4 and the jacketed engine block 5 having an outlet connection 6 with theinlet header 1 of the radiator and being supplied with water from thepump 2 which is joined by the connection 8 with the outlet header 9 ofthe radiator.

For filling the system, the top tank is providedwith a rearwardextension III which has 3, 1936, Serial No. 99,200

(Cl. 22o-24) l y in the top wall, a filling opening defined by adependent annular flange II and an upstanding spout I2. The spout isclosed by a removable cap I3 which may comprise a sheet metal stampingand the connection between the cap `and spout may be of any conventionaltype, as fo example, the familiar bayonet slot connection by which thecap is applied or removed by partial rotation thereof, Accordingly, thecap has riveted or otherwise secured internally thereof, a disc I4.which clamps in place the sealing gasket I5 and carries atdiametrically opposite points dependent legs I6 terminating in outwardlyextending feet II, and the spout in turn is provided with a camming edgeat the bottom of a dependent sleeve I8 for engagement with the feet orlugs I1. The sleeve I3 is formed as a part cf the inturned flange I9 onthe spout and at given points both the flange and the sleeve are cutaway as at 2D in-Figure 4 to allow the passage of the lug I1 when thecap is moved axially of the spout with thelugs alined with the slots.

In the present case the disc I4 also carries .a pair of spaced arms 2|having axially elongated slots 22 through which extend a transverse rodor shaft 23, the ends of which are riveted or peened over the ears 24-on a stamped cup 25, constituting a plunger or piston. By reason of thepin and slot connection 23-22, the plunger is assembled as a unit withthe cap and is permitted an axial movement relative to the cap withinlimits defined by the slot. This plunger is so constructed as to have asliding fit within the dependent annular flange II for closing thefilling opening when the capV is in its retained position on the llerspout I2. Also mounted on the pin 23 is the curled eye 26 on `one end ofa coil spring 21, which seats at the other end within a pocket on thetop of a disc valve 28, seated by the spring over an opening intheplunger 25 and guided for outward movement against the resistance of thespring, by a'series of spaced guide fingers 29 projecting into theopening. The spring is so selected as to allow the valve to openoutwardly under internal pressure of predetermined value forcommunicating the interior of the system with the filler spout, fromwhich leads the usual overflow pipe 30 extending outwardly anddownwardly beside the radiator core for discharge at the bottom of the iradiator assembly.

Inside the spout there is secured t0 the wall thereof a semi-circularstrip 3| terminating in a pair of oppositely positioned inturnedabutmentlugs 32 and these lugs are adapted for engagement byv bifurcatedears 33 extending outwardly from the upper edge of the plunger 25. Thecooperating interengaging parts 32 and 33 are so positioned withrelation to each other and the the plunger.

retained position of the ller cap I3 that the presence of internalpressure within the system will lift the plunger 25 for keying the parts32 and 33 to lock the cap against rotation. Thus after the cap is oncepositioned on the iller spout it can be removed Vonly when the plungeris in the retracted position and, therefore, the likelihood of damagecaused by gushing of hot water and steam through the filler spout byinternal pressure is eliminated.

The nt of the plunger 25 within its guide flange l I is such as to allowfree relative movement, and while sealing means may be added to reduceleakage, it is preferred merely to provide a close running fit. This maypermit a slight ilud escape without material detriment to satisfactorysystem operation and will relieve low pressure when the spring pressedvalve 28 is closed. The clearance may be quite large if the system isoperated open to outside pressure without disturbing the locking actionof the plunger. In other words, the operation of an open system undercertain conditions is such that pressure builds up at a rate higher thanthe capacity of the overflow pipe to relieve it, and the automaticlocking of the closure cap is a safety factor to avoid seriousconsequences.

With a close fit between the piston plunger 25 and ilange l l thecooling system operates, after an initial warm-up period, under a slightinternal pressure which raises the boiling point of the liquid forincreased cooling eiliciency and conservation of the liquid supply.Excess pressure is prevented through the automatic action of the reliefvalve 28. Subatmospheric pressure withn v the system is avoided by theprovision of a small bleed hole or vent port 34 in the skirt of theplunger 25, so positioned that the port 34 is closed by the cylindricalwall or flange II when the plunger is raised, but is uncovered below theflange whenever the plunger is dropped in the absence of internalpressure.

Figure 6 illustrates the application of the pressure control device to acap and illler spout of the type having^ external attachments. In thiscase the filler spout I 2 has an outturned ilange I9' from which extendsdownwardly the cam skirt I8' for engagement by a pair of diametricallyopposite inturned lugs l1' on the closure cap I3. `liotatably mounted onthe cap are a gasket 35, of rubber or the like, and a pressure ring 36of spring metal for peripheral sealing engagement with the top flan'geI9 of the spout. At their inner margins, the rings 35 and 36 have aloose t within a shouldered portion of the mounting element I4? rivetedor otherwise secured to thecap. The low-- er ends of the dependent arms2|', below the slots for Vthe transverse shaft 23 of the plunger 25', inthis instance, are offset inwardly as at 31 to aiord a seat for a coilspring 38'which bears against the bottom of the plunger. The optionaladdition of the spring 38 may be made to insure a more positive downwardor return action of The construction and operation otherwise is asbefore described.

We claim:

1. An engine cooling system having a filling opening, an upstandingspout surrounding said opening, an overiiow vent pipe leading from saidspout beyond said lling opening, a closure cap rotatably engageable withsaid spout for movement to and from its closed position, a plungeriltted to said opening to restrict system communication with said ventpe, an outwardly opening valve associated with aid plunger tocommunicate the system with the vent pipefor the relief of abnormalinternal pressure, means joining the plunger and cap for unisonalrotation whilepermitting relative axial movement of the plunger in saidopening and means carried by the spout for engagement with the plungerin its pressure projected position to lock the closure cap againstrotation.

2. An engine cooling system having a filling opening, an upstandingspout surrounding said opening; an overilow vent pipe leading from saidspout beyond said iilling opening, a closure cap rotatably engageablewith said spout for movement to and from its closed position, a pair ofspaced arms on the cap depending into the spout and having transverselyalined laxially elongated slots therein, a transverse shaft projectingbetween l'said arms and into said slots for axially guided movement, aplunger carried by said shaft and tted to said opening, an outwardlyopening valve adapted to close. a port in the plunger, a springinterposed between said shaft and valve, and interlocking formations onthe plunger and spout adapted for engagement when the plunger isprojected outwardly by internal system pressure.

3. A radiator closure, including a rotatable cap adapted for removableengagement with a illler spout, .a pressure actuated plunger, meansjoining the cap and the plunger for rotation in unison and for relativeaxial movement and an abutment on said plunger adapted to be projectedinto interlocking relation with a stop on a filler -spout.

4. In an engine cooling system having a ller spout and a removableclosure cap, a plunger movably supported on the cap and adapted forrelative movement in response to internal system pressure, and means onthe spout to be engaged by said plunger to preclude removal of the cap.

5. In an engine cooling system having a vented ller spout and aremovable closure cap, a pressure actuated piston carried by the cap andslidably iltted to a cooperating portion of the spout, cap locking meansengageable by the piston, and a vent port in the piston Wall which isclosed by said spout portion when the piston is in engagement with saidlocking means.

6. In an engine cooling system having a vented filler spout and aremovable closure cap, a pressure actuated piston carried by the cap andslidably iltted to a cooperating portion of the spout, cap locking meansengageable by the piston, a vent port in the piston wall which is closedby said spout portion when the piston is in engage- 'ment with saidlocking means, and a pressure actuated valve in said piston to relieveexcess system pressure through the vented spout.

7. In an engineA cooling system, a vented illler spout, a closuretherefor, interengaging closure locking members on the closure andspout, respectively, including a pressure actuated piston, piston guiiiemeans, and a vent in the wall of the piston adapted to be closed by saidguide means when said locking members are engaged.

8. In an engine cooling system/, a vented filler spout, a closuretherefor, interenga-ging closure locking members on the closure andspout, respectively, including a pressure actuated piston, meansassociated with the piston for relieving excess internal system pressureand other means associated with' the piston i'or relievingsubatmospheric internal system pressure.

JALIES A. WHITE. DAVID B. MECORNEY.

